BL 12 inch Mk I – VII naval gun
|origin= United Kingdom |type= Naval gun Coastal gun |is_ranged=YES |is_bladed= |is_explosive= |is_artillery=YES |is_vehicle= |is_UK=YES |service=1882–1920 |used_by=Royal Navy |wars= |designer= |design_date= |manufacturer= |production_date= |number= |variants=Mks I - VII |weight=Mk I : 47 tons barrel & breech Mk II - V 45 tonsText Book of Gunnery, 1887. Table XVI, Pages 312–313 Mk VI, VII : 46 tons |length= |part_length=Mk I & II : bore (25.14 calibres) Mk III - VII bore (25.25 calibres)Text Book of Gunnery 1902, Table XII, Page 336 |width= |height= |crew= |cartridge= |caliber= |action= |rate= |velocity= 1910 ft/second firing a 714 lb projectile, with 295 lb Brown Prismatic powder Text Book of Gunnery, 1887. Table XVI, Page 313. Text Book of Gunnery 1902 gives muzlle velocity 1914 ft/second with 295 lb brown powder or 88 lb 8 oz cordite size 30 charge. |range= at 9° 57'Text Book of Gunnery, 1887, Table XIV, Page 308. |max_range= |feed= |sights= |breech= |recoil= |carriage= |elevation= |traverse= }} The BL 12 inch naval gun Mk I was a British rifled breech-loading naval gun of the early 1880s intended for the largest warships such as battleships and also coastal defence. It was Britain's first attempt to match the large guns being installed in rival European navies, particularly France, after Britain transitioned from rifled muzzle-loading guns to the modern rifled breech-loaders somewhat later than the European powers. Mks I - VIIMk I = Mark 1, Mk VII = Mark 7. Britain used Roman numerals to designate marks (i.e. models) of ordnance until after World War II. Hence this article describes the first seven models of British BL 12-inch guns all had a barrel of approximately 303 inches in length (25.25 calibres) and similar performance. Naval service Mk II was installed on battleships from 1882, and the coastal service ironclad . Mk II guns failed in service and were quickly replaced by Mks III. IV and V, with many changes and improvements. The later marks were also mounted on , sistership of Conqueror, and on , sister ship of Colossus. Coast defence gun Mks I, VI and VII were coast defence versions with trunnions for mounting on recoil slides. They were installed in forts in England at Spitbank Fort, No Man's Land Fort and Horse Sand Fort from 1884 onward and were in active service during World War I.Hogg & Thurston 1972, pages 188-189. Ammunition File:BL 12 inch Palliser shot Mk II diagram.jpg| Mk II Palliser shot See also *List of naval guns Notes References Bibliography * Hogg, I.V. and Thurston, L.F. (1972). British Artillery Weapons & Ammunition 1914-1918. Ian Allan, London. * Text Book of Gunnery, 1887. London: Printed for His Majesty's Stationery Office, by Harrison and Sons, St. Martin's Lane * Text Book of Gunnery, 1902. London: Printed for His Majesty's Stationery Office, by Harrison and Sons, St. Martin's Lane External links *Handbook for the 12-inch B.L. 47 ton gun Mark I, VI, VII, 1891 at State Library of Victoria *Rob Brassington, Dreadnought Project : detailed Mk IV gun description and diagrams *Tony DiGiulian, British 12"/25 (30.5 cm) Marks I and II *Tony DiGiulian, British 12"/25 (30.5 cm) Marks III, IV, V and Vw Category:Naval guns of the United Kingdom Category:305 mm artillery Category:Victorian-era weapons of the United Kingdom Category:Coastal artillery